Change how draftbot picks cards during draft tournament.

First, I'm not a skilled Java program, so changes I made might not be appropriate. My daily work is about data analysis using SAS, and my last time writing some Java codes dates way back in college.

My friends and I do many sealed games using MAGE, and it's great. After sometime, we tried doing draft by adding some draftbots due to fewer people. The changes made here a make us feel the draftbot picks cards somewhat better.
We thought it might be helpful if somebody want to do similiar draft games like we do.